However, supermarkets can potentially offer other value factors -- convenience, wider selection, lower prices, job opportunities, and civic activities -- that are denied to communities that rely primarily on corner stores and small groceries. In other words, the study doesn't necessarily let the supermarket industry off the hook. Rather, it indicates that the brick-and-mortar solution is more complicated than simply bringing more food into food deserts.

What is a food desert?

Before getting to that new study, let's take a quick look at some earlier research that puts the brick-and-mortar approach to food deserts into question. In 2014, for example, PBS reported on a Philadelphia study showing that the introduction of a new supermarket did not significantly change local eating habits, though it did improve residents' perception of their neighborhood.

In 2015 the University of Minnesota released similar findings in a study titled, "Current Challenges in Determining the Impact of Food Deserts on Urban Childhood Nutrition and Health." It presents two main evidence-based findings:

Many urban residents have limited access to healthful and affordable foods.

Children are most vulnerable to the growth and health impacts of poor nutrition.

The main findings also include two items indicating that there is simply not enough evidence to answer crucial questions:

It is unclear how living in an urban area with limited access to healthful and affordable food contributes to childhood growth and health.

Numerous interventions have been proposed to address food deserts, however, limited scientific evaluations have been found that examine their specific impact on childhood health.

More broadly, the Minnesota study notes that the term "food desert" may not necessarily be a helpful framework for seeking solutions to a complex and multi-faceted issue:

‘Food desert’ is an emotionally charged term with no commonly accepted definition.

Interestingly, back in 2011 USDA offered a specific definition for "food desert." The transition in framing to "food access" seems intended to defuse the charged atmosphere noted by the Minnesota study. The USDA Food Access Research Atlas, for example, was initially launched in 2011 as the "Food Desert Locator."

For the record, here is the 2011 definition as articulated in a USDA press release announcing the launch of the Food Desert Locator:

A food desert is a low-income census tract where either a substantial number or share of residents has low access to a supermarket or large grocery store. "Low income" tracts are defined as those where at least 20 percent of the people have income at or below the federal poverty levels for family size, or where median family income for the tract is at or below 80 percent of the surrounding area's median family income. Tracts qualify as "low access" tracts if at least 500 persons or 33 percent of their population live more than a mile from a supermarket or large grocery store (for rural census tracts, the distance is more than 10 miles).

Under the current name of Food Research Atlas, USDA explains -- at great length -- that "food desert" may be defined in different ways. Here is an introductory snippet:

There are many ways to measure food store access for individuals and for neighborhoods, and many ways to define which areas are food deserts—neighborhoods that lack healthy food sources. Most measures and definitions take into account at least some of the following indicators of access:

Accessibility to sources of healthy food, as measured by distance to a store or by the number of stores in an area.

Individual-level resources that may affect accessibility, such as family income or vehicle availability.

Neighborhood-level indicators of resources, such as the average income of the neighborhood and the availability of public transportation.

Food deserts: it's complicated

The new study confirms that resolving the food desert issue is not as simple as improving access to food simply in terms of geographical location or access to transportation.

The full study, titled "The Geography of Poverty and Nutrition: Food Deserts and Food Choices Across the United States," was developed by economists from New York University, Stanford University and the University of Chicago." It is available online, but for those of you on the go the CityLab section of The Atlantic provides a good rundown.

Do read the full CityLab article for full details, but the gist of it is that the biggest differences in nutritional outcomes are not necessarily derived from where people live in relation to food sources, but from "deeper, more fundamental differences in income and, especially, in education and nutritional knowledge, which shape our eating habits and in turn impact our health."

The findings do confirm commonly accepted knowledge about food deserts...

The study reinforces the notion that food deserts are disproportionately found in disadvantaged neighborhoods. It finds that more than half (55 percent) of all ZIP codes with a median income below $25,000 fit the definition of food deserts—that’s more than double the share of food-desert ZIP codes across the country as a whole (24 percent).

...but they also indicate that improving access to healthy food does not automatically translate into improvements in nutritional health:

Opening new supermarkets has little impact on eating habits of people in low-income neighborhoods: Even when residents do buy groceries from the new supermarkets, they buy products of the same low nutritional value.

Healthy foods are generally thought to be more expensive, but the study also finds that cost is also a relatively insignificant factor:

...While healthy food costs a little bit more than unhealthy food, most of that is driven by the cost of fresh produce. There is only a marginal price difference between other healthy versus unhealthy eating options. Furthermore, the price gap between healthy and unhealthy food is actually a little bit lower than average in many low-income neighborhoods, according to the study.

So, what's the solution?

To be clear, the new study presents just one aspect of a larger problem. As a standalone piece it does not necessarily demonstrate that building more supermarkets is an ineffective way to allocate resources for improving community health, but it does add to a body of knowledge showing that a simple brick-and-mortar solutions are not adequate.

That is a challenge, but it also leaves the door open for a wide range of corporate social responsibility opportunities.

The New Jersey based nonprofit organization Uplift Solutions, for example, offers a holistic pathway for supermarkets to progress from simple food availability to healthier choices, changes in habit and improved nutrition. This pathway engages supermarkets as change agents:

...full-service supermarkets in underprivileged communities can become the cornerstone to fulfill a multitude of community needs. To actualize this belief, Uplift takes a multidisciplinary approach, leveraging its four program areas to deliver new supermarkets creating access to fresh and healthy food; preserve existing supermarkets to maintain access to fresh and health food; develop new health clinics to create access to preventative and restorative health care services; and collocate wraparound services to provide access to nutrition education and public benefits.

Uplift also challenges the evidence that new supermarkets do not change habits. Over the long run, the organization has noted shifts in habits as local residents become accustomed to using a new store.

Supermarkets can also help introduce healthy choices in other ways. The regional New Jersey ShopRite chain, for example, recently launched a "Kids Klub" card that entitles children to a free item of fresh produce when shopping with an adult. Participating in or donating to local nutrition initiatives is another option for major chains, including school based educational programs.

In broader terms, the growing body of food desert research could help major retail food chains think about tackling the problem in the same way that forward-thinking corporations approach other corporate social responsibility initiatives. The direct bottom line benefits may not be clear at first, but as companies engage more closely with local communities, the long term advantages of meeting today's challenges will reflect a company's ability to survive -- and thrive.

Tina writes frequently for TriplePundit and other websites, with a focus on military, government and corporate sustainability, clean tech research and emerging energy technologies. She is a former Deputy Director of Public Affairs of the New York City Department of Environmental Protection, and author of books and articles on recycling and other conservation themes. She is currently Deputy Director of Public Information for the County of Union, New Jersey. Views expressed here are her own and do not necessarily reflect agency policy.